1. Field
Aspects of embodiments of the present disclosure relate to a display substrate improved in terms of a display quality, a liquid crystal display (“LCD”) device including the display substrate, and a method of manufacturing the LCD device.
2. Description of the Related Art
Display devices are classified into liquid crystal display (“LCD”) devices, organic light emitting diode (“OLED”) display devices, plasma display panel (“PDP”) devices, electrophoretic display (“EPD”) devices, and the like, based on a light emitting scheme.
An LCD device generally includes a display substrate including an electrode formed thereon, an opposing substrate, and a liquid crystal layer disposed between the display substrate and the opposing substrate. Recently, a color-filter on array (COA) structure is applied to LCD devices in which a color filter is disposed on a display substrate to improve transmittance.
In an attempt to efficiently reduce or prevent misalignment arising in the process of coupling a display substrate on which a color filter is disposed and an opposing substrate on which a shielding member is disposed, a black matrix on array (BOA) structure is applied to LCD devices in which a color filter and a shielding member are disposed on the display substrate. Besides, a black column spacer (BCS) structure is developed in which a spacer for maintaining a gap between a display substrate and an opposing substrate is formed of the same material as that forming a shielding member.
The shielding member may include a black matrix pattern disposed on a gate line or a data line in a display area and a black border pattern in a non-display area around the display area. It is necessary that the black matrix pattern has a thickness less than a predetermined thickness due to a structure therebelow such as a color filter, and the black border pattern has a thickness greater than the thickness of the black matrix pattern to prevent light leakage. In addition, the black matrix pattern and the black border pattern may be formed simultaneously using a halftone mask, and in such a case, a portion of the black matrix pattern adjacent to the black border pattern may be over-etched due to loading effects.
In a conventional LCD device, in order to obviate the aforementioned issues, a portion of the black border pattern adjacent to the black matrix pattern is formed to have the same thickness as that of the black matrix pattern to prevent over-etching of the black matrix pattern that may occur due to loading effects, and a dummy color filter is disposed below a portion of the black border pattern adjacent to the black matrix pattern to prevent light leakage.
In such a case, a step difference may increase at a portion where the black border pattern and the dummy color filter overlap each other, thus causing defects of low flowability of liquid crystal molecules. That is, liquid crystal molecules may not be suitably filled in a non-display area such that cell-gap uniformity may decrease, and a display quality may be degraded.
It is to be understood that this background section is intended to provide useful background information for understanding the present disclosure and as such disclosed herein, the background section may include ideas, concepts or recognitions that were not part of what is known or appreciated by those skilled in the pertinent art prior to a corresponding effective filing date of the subject matter disclosed herein.